Senior sources claim the Cabinet 'Brexit truce' is expected to last only a few months

But senior sources say the jumbo compromise only papered over huge divisions between soft and hard Brexiteers around the PM’s top table, because “everyone walked away able to say they got what they wanted”.

The long running schism – of single market access championed by Chancellor Philip Hammond versus sovereign control lead by Boris Johnson - will reopen when the 27 EU leaders are widely expected to reject Mrs May’s opening gambit when formal negotiations begin in April.

One Cabinet minister and member of the 11-strong Brexit war committee that met at Chequers told The Sun: “It’s easy to agree on an opening position.

“What happens if that’s rejected is a lot harder, and that’s going to be a far bigger challenge.”

Another Cabinet minister added: “Thursday was the first time we’ve ever sat round table and all agreed on something.

“Plan A was hard enough. There is no Plan B. We’ll get to plan B when we need to”.

With much of the hard talking done between ministers in the tense 24 hour run up to the Chequers away day, there were no verbal dust ups during the sessions, with one attendee even dubbing it “rather dull”.

Based on the principle of “ambitious managed divergence”, Mrs May will agree to a mutual recognition of standards with the EU for manufactured goods such as the car industry, but diverge from Brussels edicts in other sectors like financial services.

EU Council chief Donald Tusk turned up the pressure on Mrs May to spell out her plan ASAP.

Mr Tusk revealed the 27 EU leaders will issue their negotiating guidelines at their next summit on March 22.

18-year-old Brexiteer Steven Edgington questions how long the European Union can really last?

He added: “Our intention is to adopt these guidelines whether the UK is ready with its vision of our future relations or not.

“Naturally it would be much better if it were, but we cannot stand by and wait.”

Mr Tusk will meet Mrs May for talks in N0.10 on Thursday next week, the day before her big speech.

In a withering attack on Mrs May’s Chequers deal, Mr Tusk abandoned any attempt at diplomatic language to say that it “looks like the cake philosophy is still alive”.

He added: “If the media reports are correct, I’m afraid that the UK position today is based on pure illusion.

“From the very start it’s been a key principle of the EU27 that there can be no cherry-picking and no single market a la carte.